• IEIE Transactions on Smart Processing and Computing
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• 제5권5호
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• pp.323-326
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• 2016

High Efficiency Video Coding (HEVC) adopts intra transform skip mode, in which a residual block is directly quantized in the pixel domain without transforming the block into the frequency domain. Intra transform skip mode provides a significant coding gain for screen content. However, when intra-prediction errors are not transformed, the errors are often correlated along the intra-prediction direction. This paper introduces a residual differential pulse code modulation (DPCM) method for the intra-predicted and transform-skipped blocks to remove redundancy. The proposed method performs pixel-by-pixel residual prediction along the intra-prediction direction to reduce the dynamic range of intra-prediction errors. Experimental results show that the transform skip mode's Bjøntegaard delta rate (BD-rate) is improved by 12.8% for vertically intra-predicted blocks. Overall, the proposed method shows an average 1.2% reduction in BD-rate, relative to HEVC, with negligible computational complexity.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 추계학술대회(제116회) 및 13회 Workshop 제3회 한ㆍ일 치과보존학회 공동학술대회 초록집
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• pp.558.2-558
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• 2001

The aims of this study are (1) to investigate the relation of irradiation mode, polymerization shrinkage and degree of cure of composite resin and(2) it effect on micorleakage of class V restorations. VIP(BISCO Dental Products, Schaumburg, IL, USA) and Optilux 501 (Demetron/Kerr, Danbury, CT, USA) curing lights were used for curing Z-250 composite resin following irradiation mode: VIP 200㎽d, VIP 400㎽, VIP 600㎽, pulse-delay(200㎽ 3sec, 5min wait, 600㎽ 30sec), Optilux R mode.(omitted)

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.1882-1885
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• 1998

This paper proposes the advanced PWM method which can reduce common-mode voltage in 3 phase PWM converter/inverter system. By shifting the zero voltage vector of inverter in a sampling period, it is possible to cancel out a common-mode voltage pulse defined by switching functions of converter and inverter. Without any loss of control performance of converter/inverter system, overall common-mode voltage can be reduced by one-third compared with that of conventional PWM scheme.

• Journal of Mechanical Science and Technology
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• 제15권10호
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• pp.1398-1407
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• 2001

In this paper an anti-lock brake system (ABS) for commercial buses is proposed based on a fuzzy-logic controller and a sliding-mode observer of the vehicle speed. The brake controller generates pulse width modulated (PWM) control inputs to the solenoid valve of each brake, as a function of the estimated wheel slip ratio. PWM control inputs at the brakes significantly reduce chattering in the brake system compared with conventional on-off control inputs. The sliding-mode observer estimates the vehicle speed with measurements of wheel speed, which is then sed to compute the wheel slip ratio. The effectiveness of the proposed control algorithm is validated by a series of computer simulations of bus driving, where the 14-DOF bus model is used.

• 전기전자학회논문지
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• 제21권4호
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• pp.375-380
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• 2017

A differential current-to-time interval converter is presented for current mode sensors. It consists of a ramp voltage generator, a current mode sensor, a reference current source, two current-tunable Schmitt triggers, a one-shot multivibrator, and two logic gates. The design principle is to apply a ramp voltage to each input of the two current-tunable Schmitt triggers whose threshold voltages are proportional to the drain current values of the current mode sensors. A proposed circuit converts a current change in the ISFET biosensor into its equivalent pulse width change. A prototype circuit built using TSMC 0.18 nm CMOS process exhibit a conversion sensitivity amounting to $726.9{\mu}s/pH$ over pH variation range of 2-12 and a linearity error less than ${\pm}0.05%$.

• 한국방사선학회논문지
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• 제6권3호
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• pp.207-215
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• 2012

광 역학치료(Photodynamic therapy: PDT) 중 하나인 기존의 LED 광 조사는 연속파(Continuous wave: C.W) 방식의 635 nm 파장으로 여드름 치유에 가장 많이 사용되어 왔으나, 이 방식은 에너지효율이 낮고 생체조직에 열이 많이 발생하여 개선의 방안이 필요했다. 본 논문에서는 에너지효율을 높이고 여드름 치료를 위하여 생체조직에서의 열적 파괴현상을 방지하기위해 PWM(펄스 폭 변조: Pulse Width Modulation)을 활용한 여드름 치료용 LED 광 조사장치를 설계하였다. 시스템 구성은 크게 Timer 모듈, PWM 모듈, 광학전달 장치로 크게 세구성하여 설계하였으며, 여드름 치료를 위한 피부 투과 깊이를 높이기 위하여 광학전달 장치는 660 nm 파장의 1 W LED를 사용하였다. PWM 제어를 이용하여 발생된 주파수와 파형을 확인하고, 660 nm LED의 출력에너지 및 생체조직의 표면온도를 확인하여 안정적인 에너지출력과 생체조직의 안정성에 대해 평가하였다. 그 결과 여드름 치료를 위한 660 nm 파장의 1 W LED 광 에너지를 얻기 위하여 C.W 방식으로 사용하였을 경우 전력손실이 높고 생체조직에서의 열적 파괴현상을 보였으나, PWM 방식을 구현함으로써 펄스 폭 변조를 통하여 LED의 전력소모를 낮추었고, 생체조직의 열적 파괴현상이 나타나지 않아 여드름 치료를 위해 사용할 경우 C.W 방식보다 PWM 방식이 더 안전하고 효과적일 것으로 사료된다.

• 대한전자공학회논문지SD
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• 제46권11호
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• pp.84-91
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• 2009

본 논문은 multi-level signaling을 이용한 high speed serial link transmitter에 관하여 제안하였다. High speed serial link에서 수 Gb/s를 달성하기 위해 4-pulse amplitude modulation (PAM) 을 사용하였다. 4-PAM은 4개의 level로 한 symbol time에 2 bit data를 전송함으로써 binary signaling보다 2배 빠른 data 전송이 가능해졌다. 제안된 4-PAM transmitter는 전압 output 대신 전류 output을 생성하며 이로 인해 driver의 switching time이 빨라져서 더 높은 속도의 transmitter를 구현할 수 있었다. $2^5-1$ pseudo-random bit sequence (PRBS) 생성기는 built-in self test (BIST)를 하기 위해 on-chip으로 설계되었다. 본 연구는 동부 하이텍 $0.18{\mu}m$ CMOS 공정을 통하여 설계되었으며 1.8 V supply voltage에서 eye 크기가 160 mV 이고 최대 동작 속도는 8 Gb/s이다. 칩 전체 면적은 $0.7\times0.6mm^2$이며 전력 소모는 98 mW이다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2003년도 제24회 학술발표회 초록집
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• pp.210-210
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• 2003

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.541-542
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• 2010

• 전력전자학회논문지
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• 제4권5호
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• pp.423-432
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• 1999

This paper proposes a 12­pulse diode rectifier system with low kVA components suitable for powering switch mode power supplies or ac/dc converter applications. The proposed 12-pulse system employs a polyphase transformer, a zero sequence blocking transformer (ZSBT) in the dc link, and an interphase transformer. Results produce near equal leakage inductance in series with each diode rectifier bridge ensuring equal current sharing and performance improvements, The utility input currents and the voltage across the ZSBT are analyzed the kVA rating of each component in the proposed system is computed. The 5th , 7th , 17th and 19th harmonics are eliminated in the input line currents resulting in clean input power. The dc link voltage magnitude generated by the proposed rectifier system is nearly identical to a conventional to a conventional 6-pulse system. The proposed system is suitable to retrofit applications as well as in new PWM drive systems. Simulation and experimental results from a 208V , 10kVA system are shown.